Hi Friends,
I just got this going. Just sharing here in case it helps someone else out. Long story short, I managed to create the api key independent of the billing. Obviously not this awesome themes fault, but the google interface is confusing as all hell. I blame the UI. Anyway, I had created the key, but it wasn’t working in the theme when I hit the “Check API key” button. I opened a new session to the google cloud url:
https://console.cloud.google.com/google/maps-apis/
And was asked which billing account I wanted associated with the current project. I selected the billing account and it all started working. : )
All the best.